OF THE MALTESE ISLANDS, 6] 
Thorax (fig. 8, p. 63). This consists largely of the meso-thoracic division, 
the prothorax being represented by a very short extension which can be seen 
more or less distinctly in examples which have been macerated and mounted in 
Canada balsam. The scutellum and post-scutellum are well developed and 
conspicuous in mounted preparations. 
Abdomen.—This is composed of ten segments, the last being modified by the 
external genitalia. In the female the appendages are simple, flattened, leaf-like 
structures, densely clothed with hairs and arranged in two pairs (figs. 8 and 10), 
In the Maltese species they are all so similar in structure as to afford no 
diagnostic characters of importance. Annandale (1) states (p. 41) that these 
organs “ become distorted and shrivelled in dried specimens.” These structures 
can, however, be restored by maceration in caustic potash but the best results 
may be obtained by preserving the specimens in alcohol. 
External genitalia of the males —These are large and complex structures 
(figs. 14-18, pp. 70-74) and afford a ready means of determining the sexes ; 
moreover, their morphological characters are of great importance as they present 
very marked specific differences whereby the closely allied species may be readily 
distinguished. These appendages are arranged in five pairs as follows :— 
Superior claspers (sc in all the figures). These are placed dorsally and are 
larger than any of the other structures; they are composed of two distinct 
segments, of which the terminal or distal one is the smaller and is provided at 
the apex with large spines, which in some species are curiously modified. They 
are generally densely hairy and large scales may aiso be present ; but both hairs 
and scales are easily deciduous and the greater portion of them usually fall 
away during the process of mounting for microscopical study. The accom- 
panying illustrations must therefore be considered as representing these structures 
in a partly denuded condition. Inferior claspers (ic). These are unisegmented 
and much shorter than the superior pair; they are ventrally placed and may or 
may rot have modified spines at the distal extremity. Swbhmedian lamellae. 
These lie between the inferior claspers, and although they are usually short, 
thin, leaf-like structures, in some instances (2. minutus) they are very similar to 
the clasper both inform and length. Intermediate appendages (ia). These occupy 
a median position and are often curiously modified ; they form a branch of the 
superior clasper and are sometimes bi-lobed. IJntromittent organ (to). This is 
homologous with the “juxta” in Glossina, and is described as the penis by 
Grassi. It consists of a pair of long slender and highly chitinised organs which 
lie between the intermediate appendages. These completely ensheath the two 
long filamentous processes which form a continuation of the ejaculatory duct 
leading from the penultimate segment of the abdomen. In P. papatasii they 
have not been seen to extend beyond the intromittent organ or penis, while in 
P. perniciosus (figs. 16, 17, p. 72), though lying apparently in a normal resting 
position, they project beyond it to a distance equalling one-half the length of the 
sheath. 
Wing.—This is densely hairy, and may at once be distinguished from that of 
the mosquitos (CULICIDAE) by the entire absence of scales, the double fork 
of the second longitudinal vein, and the proximal position of the cross-veins, 
